PCM Problem?
Thread Starter
Banging some gears
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From: Mississippi
PCM Problem? Well just recently my car threw the crank sensor code... p0335.. so i replaced the sensor, cranked the car up, and still same problem- backfireing, won't idle, tach signal working at times, not working at times.... i looked all the wires over the best i could and found nothing wrong... so i took it to a local dealership and had them look over it for me. They "found a problem" in the wiring harness so they just ran new wires from the sensor to the pcm, bypassing the main harness... called me told me they had fixed it and it was ready to be picked up...i get there and ask how much i owe em and i was told $481.50!!!!!!!! ok nothing i can do about that so i just payed the folks and was on my way.. so im driving the car to a friends house and the tach quits working, well i keep driving that way b/c im in the middle of BFE and dont want to break down there right... make to his place..car still running fine but the tach is still working when it wants to. eventually the car just quit running, backfiring and no tach signal.... anyone have any ideas of what else this could be... im thinking PCM b/c as far as i know i've pretty much illiminated everything else!
please help,
Daniel
please help,
Daniel
Did they replace the female connector pins in the connector, or just butt connect the new wires into the old wires at the sensor connector? The proper repair would have been to crimp new female pins and run 1 piece wires to the PCM and crimp new pins on that end too.
I assume you have headers? Did you check to see that the wires werent burnt on the header?
If they just butt connected some wires in, you will want to check the female pins in the connector. They have a bad habit of opening up and causing intermittent problems.
I assume you have headers? Did you check to see that the wires werent burnt on the header?
If they just butt connected some wires in, you will want to check the female pins in the connector. They have a bad habit of opening up and causing intermittent problems.
Burnt or loose wires somewhere, most likely.
Especially where they are near the exhaust, or near the seam between the engine and trans to get pinched on a trans install.
Possibly loose grounds under the dash near the kick panels.
Especially where they are near the exhaust, or near the seam between the engine and trans to get pinched on a trans install.
Possibly loose grounds under the dash near the kick panels.
Thread Starter
Banging some gears
iTrader: (10)
Joined: Sep 2005
Posts: 868
Likes: 0
From: Mississippi
thanks for the help... little update on the situation. i was working on the car the other day, (wiggling wires) and could get nothing to happen.. looked all the wires around the trans over best i could, still found nothing.. car still cranks up fine when its dead cold, but as soon as it warms up it runs like *****! i unhooked my battery and pulled the pcm out to get the serial number off of it put it back in and the car ran fine (like it should run) for a coulple of hours. so i took it to the dealership and got them to try a crank relear again. still didnt work. noticed that i had my bank 1 sensor 1 plugged into the bank 1 sensor 2 location... fixed that then tried a realearn and it worked this time!?! now what the sensor had to do with it i have no idea. to make the story short i left the dealer and made it to my house with the car and it quit running and now is doing the same as it was! PCM??
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Thread Starter
Banging some gears
iTrader: (10)
Joined: Sep 2005
Posts: 868
Likes: 0
From: Mississippi
DTC was p0336 (crank sensor) so i replaced the crank sensor and still didnt fix the problem... still threw a crank sensor code. so i took it to the dealer and they said it had a low voltage code to the crank sensor so they replaced the wires and did a crank relearn on the car... still nothing.. i bought a pcm for 40 bucks and am gonna get it flashed and see if that fixes it...
Thread Starter
Banging some gears
iTrader: (10)
Joined: Sep 2005
Posts: 868
Likes: 0
From: Mississippi
You could have checked the wiring harness yourself using a DVOM. All you had to do was disconnect the harness at both ends and check for shorts(to ground and to other harness wires) and opens. You're not likely to have thses problems unless you recently installed headers or did an engine or transmission swap or had a bad wreck where the chassis was affected. You don't need to be a mechanic(mechanics turn wrenches) to do that. You need to be an electrician or an electronic technician. That just means you need to be able to read an meter and know ohms law which a lot of mechanics do. Since you've replaced the sensor and harness the PCM is suspect since it has resently been replaced. That would have been my first place to look since it is the most recent item that was swapped out. That's always the place to start looking.
